Conventionally, there is known a technology using a long plate-like magnet formed by dividing a long magnet into a plurality of magnet pieces and integrating the plurality of divided magnet pieces as a magnet to be inserted into a magnet insertion hole of a rotor core of a motor to reduce an eddy current possibly generated in the magnet (see JP2009-142081A). In a method described in JP2009-142081A, the long magnet provided with cuts is placed on a lower punch and cut at the position of the cut by pressing an upper punch downwardly from above the long magnet.
Here, in the cutting method of JP2009-142081A, it is considered to provide a pair of supporting portions instead of the lower punch, set the long magnet so that the cutout is located between the pair of supporting portions and the magnet is cut by three-point bending by the pair of supporting portions and the upper punch. To improve the accuracy of a cut surface, an interval between the pair of supporting portions is better to be wide. However, if the interval is too wide, there is a possibility that the magnet piece falls down between the pair of supporting portions after cutting. Further, in setting the magnet at the next cutting position by pushing it in a lateral direction such as when burrs are present on the magnet after cutting, there is a possibility that the magnet after cutting is caught by the pair of supporting portions.
The present invention aims to prevent a magnet piece after cutting from falling down between a pair of supporting portions and prevent a magnet from being caught by the pair of supporting portions at the time of feeding the magnet.
The magnet cutting device in embodiment of the present invention includes a pair of supporting portions spaced apart by a predetermined distance, the pair of supporting portions being configured to support the magnet from bottom side of the magnet, a pressing portion configured to press the magnet supported by the pair of supporting portions from a upper side of the magnet, and a magnet supporting tool arranged between the pair of supporting portions to support the magnet from the bottom side of the magnet, the magnet supporting tool being configured to be vertically movable. A surface of the magnet supporting tool to be held in contact with the magnet is shaped such that a central part of an upper end of the magnet supporting tool is higher than the upper ends of the pair of supporting portions and an end part of the upper end of the magnet supporting tool is lower than the upper ends of the pair of supporting portions in a state where the magnet is placed on the surface, the upper end of the magnet supporting tool having a slope connecting the central part and the end part.
Embodiments and advantages of the present invention will be described in detail below with reference to the attached figures.